Scoring Guide: Quarter 1 Review: Science

Read each question. Circle the answer, write it on the lines or draw it in the box.

1. 1.

   Eli slides a heavy box away from himself across the garage floor. Is he using a push or a pull?

   (1 pt)

   Answer: push

2. 2.

   A kickball rolls slowly past Marcus. He kicks it from behind, in the same direction it is already rolling. What does his kick do to the ball's motion?

   (1 pt)

   Answer: It makes the ball speed up (roll faster).

3. 3.

   A wagon sits still on the sidewalk. Caleb pulls the handle forward with a strong pull. His little sister holds the back of the wagon and pulls backward with a weak pull. a) Draw the wagon and one arrow for each pull. Make the longer arrow show the stronger pull. b) Are the forces balanced or unbalanced? c) Which way does the wagon move?

   (3 pts)

   Answer: a) Two arrows pointing in opposite directions, with the forward arrow (Caleb's pull) longer than the backward arrow. b) Unbalanced. c) Forward, the way Caleb pulls (toward the stronger pull).

4. 4.

   A skateboard rolls across flat pavement with no one on it. It gets slower and slower and then stops. While it was slowing down, were the forces on it balanced or unbalanced? How do you know?

   (2 pts)

   Answer: Unbalanced, because its motion was changing (it was slowing down). Friction from the pavement was slowing it.

Read about Ruby's test. Use the table to answer questions 5 to 8. Question 9 is a new problem.

1. 5.

   Name two things Ruby must keep the same on every trial so that her test is fair.

   (2 pts)

   Answer: Any two: the same sneaker, the same rubber band, pulling the same way (slowly, at the same speed), measuring the stretch the same way.

2. 6.

   Ruby wants one number to stand for the wood deck. She puts her three stretches in order from shortest to longest. Which one is in the middle?

   (1 pt)

   Answer: 9 cm (in order: 8, 9, 10)

3. 7.

   Which surface has the most friction? How does the table show it?

   (2 pts)

   Answer: The doormat. The rubber band stretched the most there (13 to 15 cm), so the sneaker needed the strongest pull.

4. 8.

   Ruby says, "The tile floor is so smooth that it has no friction at all." Is she right? Use the table to explain.

   (2 pts)

   Answer: No. The rubber band still stretched 4 to 6 cm on the tile, so a pull was still needed. The tile has less friction, but some friction is there.

5. 9.

   Children say the playground slide is too slow. Should the workers make the slide's surface smoother or rougher? Explain. Use the word friction.

   (2 pts)

   Answer: Smoother. A smoother surface has less friction, so less force slows the children and they slide faster.

Think about forces that can act without touching.

1. 10.

   Write YES if a magnet will attract the object. Write NO if it will not. ___ a steel sewing needle ___ a glass marble ___ an aluminum soda can ___ an iron frying pan

   (2 pts)

   Answer: YES, NO, NO, YES

2. 11.

   Two toy train cars have a magnet on each end. When Amir brings two cars together one way, they snap together. When he turns one car around, the cars push apart. Explain both results. Use the word poles.

   (2 pts)

   Answer: They snap together when opposite poles face each other (north and south), because opposite poles attract. They push apart when the same poles face each other (north and north, or south and south), because like poles repel.

3. 12.

   Lucy holds a magnet above a pile of steel pins. From 10 cm away, nothing happens. From 2 cm away, the pins jump up to the magnet before it touches them. a) Is magnetism a contact force or a non-contact force? b) Why did the pins jump at 2 cm but not at 10 cm?

   (2 pts)

   Answer: a) A non-contact force. b) A magnet's pull is stronger when it is closer and weaker when it is farther away. At 10 cm the pull was too weak to lift the pins.

4. 13.

   Wes pulls off his wool hat on a dry day. His hair stands up and reaches toward the hat. Which force is pulling his hair?

   (1 pt)

   Answer: static electricity

Answer questions 14 and 15 about patterns. Then read Ivy's problem and answer questions 16 and 17.

1. 14.

   Grace's pendulum is a small bag holding 5 marbles on a string. It makes 14 swings in 20 seconds. She puts 10 more marbles in the bag and keeps the string the same length. Predict about how many swings it will make in 20 seconds now. Explain.

   (2 pts)

   Answer: About 14 swings (the same). A heavier weight does not change the number of swings much. Changing the length of the string is what changes it.

2. 15.

   Henry drops a ball and measures each bounce: 80 cm, 40 cm, 20 cm, 10 cm. Predict the height of the next bounce. Tell how you used the pattern.

   (2 pts)

   Answer: About 5 cm. Each bounce is about half as high as the one before, and half of 10 is 5. Also accept any height lower than 10 cm with the reason that each bounce is lower than the one before.

3. 16.

   Write CR for a criterion or CO for a constraint in Ivy's problem. ___ The holder keeps the scissors from falling. ___ Ivy may use only 1 magnet. ___ Ivy has 20 minutes to build. ___ Ivy can take the scissors off with one hand.

   (2 pts)

   Answer: CR, CO, CO, CR

4. 17.

   To make the holder look nice, Ivy rolled the foam into a thick pad and taped it over the magnet. In her test, the scissors slid off the pad and fell. Use what you know about magnets to explain why. Then name one change she should test next.

   (3 pts)

   Answer: The thick pad put the magnet farther from the scissors, and a magnet's pull gets weaker as the distance grows. Change: make the cover thinner (one flat layer of foam, or none) and test again.